Effect of bismuth oxide introduction on spectroscopic properties of Er3+/Yb3+ co-doped aluminophosphate glasses

The absorption spectra, emission spectra and infrared spectra of Er3+/Yb3+ co-doped xBi2O3-(65 − x)P2O5-4Yb2O3-11Al2O3-5BaO-15Na2O were measured and investigated. Spontaneous emission probability, radiative lifetime and branching ratios of Er3+ were calculated according to the Judd-Ofelt theory. The role of substitution of Bi2O3 for P2O5 on luminescence of Er3+/Yb3+ co-doped aluminophosphate glasses has been investigated. The calculated radiative lifetimes (τrad) for 4I13/2 and 4I11/2 were decreasing with Bi2O3 content increases, whereas the measured total lifetime (τmeas) for 4I13/2 showed linearly increasing trends. The effect of Bi2O3 introduction on OH− groups was also discussed according to the IR transmittance spectra of glasses. It was found that FWHM of glasses were not affected with the substitution of Bi2O3 for P2O5. The emission spectra intensity increased with Bi2O3 content due to the decreases of phonon energy and OH− content in glasses.